This is a renewal application for a training program designed to produce Ph.D.s in immunology. We currently have 39 predoctoral students. Rather than a biology or microbiology program which includes immunology, ours is one of a relatively small number dedicated to training in immunology. As our 19 member faculty contains scientists with medical training and interests, we provide an appreciation of clinical problems together with basic technical expertise, scientific insight and involvement with important scientific problems. The didactic program consists of a series of required courses (Biochemistry, Introduction to Immunology, Immunogenetics, Immunochemistry, Immunological Mechanisms of Disease) and electives in molecular biology, biochemistry and cell biology. These are supplemented by required participatory courses (Journal Club, Seminar and Student Workshop). No more than one grade below B- is allowed for these courses. Students take four laboratory rotations during the first year and pass a qualifying examination before selecting a thesis advisor and a thesis research project. This research is considered the core of the training. Requirements and expectations are established in writing and an active student advisor program keeps students well informed of their progress. While a thesis mentor is responsible for supplying day to day direction, a thesis advisory committee must be satisfied with the project proposal and sustained student progress. A thesis must be written and defended as demonstrating an original and substantive contribution of scientific knowledge. Publication is not a specific requirement for a degree, but most graduates are authors of peer-reviewed papers. As part of the program students are trained in communicating data and participating in analytic discussion. The program successfully trains a high proportion (91%) of all entering students. Similarly, a high proportion of graduates (97%) are in science and 87% are currently active and productive research scientists. We are seeking support for four students for two years each (a total of eight traineeships.) Support for five years is requested. Selection of students is based on grades, GRE scores, recommendations, previous research experience and interviews. The selection committee includes five faculty members and two senior students. Over the past five years, a period in which the number of applicants seeking predoctoral training in science has declined nationally, our applicant pool has increased in size and quality and is currently at the level of 133 for four or five positions. Approximately 100,000 square feet of well-equipped laboratory space is available, including flow cytometry, semi-automatic sequencing, transgenic facility, digital imaging and multiple faculty laboratories. These are located in the Tufts University School of Medicine and the New England Medical Center.